1. Field of the Invention
The present invention relates to the field of photography and, more particularly, to miniature selfdeveloping cameras.
2. Description of the Prior Art
The term -miniature- as used in this disclosure in connection with self-developing cameras is descriptive of the relatively small physical size of both the camera and self-developing film units used therein. In general, these cameras are configured for use with a small format self-developing film unit that has an image forming area more closely approximating a 35mm frame than the much larger and more conventional "snap shot size" frame.
Most miniature self-developing cameras found in the prior art are configured for exposing and processing "instant slides", i.e., positive image transparencies which are premounted in a cardboard or plastic frame to facilitate viewing or projection subsequent to processing. Some of these cameras also include an integral or attachable magnifying slide viewer so that the photographer may examine the details of the slide after processing.
Generally, such cameras include a supply chamber or receptacle for holding a stack of instant slides or receiving a cassette or magazine having a stack of slides preloaded therein, an exposure station where a slide is located for exposure, pressure applying means for applying a compressive pressure to the exposed film unit to release a fluid processing composition from a rupturable container on the film unit and to distribute the fluid between predetermined layers of the film unit thereby initiating a development of diffusion transfer process, an imbibition chamber or station providing a light tight environment for the film unit after fluid distribution to protect the film unit from further exposure until the processing is complete; and a film transport system for moving the film unit between its various positions within the camera housing during a cycle of camera operation.
For representative examples of the prior art relating to miniature self-developing cameras, reference may be had to U.S. Pat. Nos. 2,854,903; 3,255,670; 3,350,990; 3,369,469; 3,369,470; 3,421,423; 3,437,023; 3,437,024; 3,446,127; 3,446,131; 3,455,222; 3,541,939; 3,541,940; 3,541,937; 3,541,938; 3,575,081; 3,525,293; 3,614,920; 3,648,527; and 3,636,844.
A major deficiency of the prior art camera relates to the handling of the small transparency slides after processing. The very nature of a small format transparency slide requires that it be carefully handled and stored because finger prints, dust, and small particles of dirt thereon are highly visible when the image on the slide is magnified for direct viewing or projection onto a screen.
To varying degrees, all of the above-noted prior art cameras require that the photographer manually handle the transparency slide after processing, thereby significantly increasing the possibility that slides will become contaminated by finger prints, dust, etc.
For example, with the exception of the camera described in the above-noted U.S. Pat. No. 3,350,990, all of these cameras require the removal of a processed slide from the imbibition chamber before the next film unit in the camera can be processed. At the very minimum, the user must interrupt his picture taking to remove the processed slide and find a dirt and dust free environment for its storage. The camera described in U.S. Pat. No. 3,350,990 has an imbibition chamber which is sufficiently large to receive all of the film units initially loaded into the camera, but if the user wishes to view his results before taking the next picture, he must open the chamber door, manually remove the processed slide therefrom for viewing and then manually reinsert the slide for storage.
the previously noted U.S. Pat. Nos. 2,854,903; 3,255,670; 3,446,127; 3,446,131; and 3,575,081 all include an integral or attachable magnifying slide viewer. Again, the use of the slide viewer is accompanied by the requirement for manually handling of the slide. It must be removed manually from the imbibition chamber and inserted into the viewer.
The camera described in U.S. Pat. No. 2,854,903 uses a transparency film unit having a strippable opaque backing sheet on the under side thereof. This backing sheet is used to prevent exposure by transmission of the underlying slides in the stack when the forwardmost slide is exposed. After exposure, the slide is advanced between a pair of pressure rollers and into a combination imbibition chamber/viewing station. In this position, the backing sheet is used to prevent light passing through a slide viewer eye lens from further exposing the slide until the imbibition period is over. The user then opens the slide viewer door and manually removes the backing sheet. He then closes the door from viewing. Because the imbibition chamber/viewing station has the capacity to hold only one slide at a time, the processed slide must be removed manually before the next slide can be processed. Therefore, the slide is handled twice, once for stripping the backing sheet and once again upon removing the slide from the camera for storage after viewing.
It will be noted that the previously mentioned U.S. Pat. No. 3,541,940 describes a film container or slide magazine having a supply chamber for holding a stack of unexposed transparency film units and a storage chamber for storing the slides after processing. But, once again the photographer is required to manually remove the processed slide from the camera imbibition chamber and insert into the magazine storage chamber.